Conventional heat exchangers utilized for internal combustion engines or similar applications generally include distribution headers extending across the opposite ends of heat exchanger cores and receiving a plurality of coolant tubes projecting therethrough to be in fluid communication with inlet and outlet tanks, which are secured to the headers in a liquid-tight condition. Each header and tank is provided with peripheral flanges having openings through which extend clamping bolts to secure the parts together. This is typical in heavy duty radiator applications. Some automotive radiators solder header to tank providing a leakproof joint. Other applications use plastic tanks with metal headers. These headers are formed in such a manner to provide tabs around the periphery of the header. During final assembly these tabs are folded onto the tank thus providing a clamping pressure on a resilient gasket positioned between the flanges to be deformed and sealingly engage the flanges under the pressure exerted by the clamping means to insure a liquid tight joint.
Several problems may arise in the above structural arrangements. One is the problem of galvanic corrosion between the clamping bolts, header and tank. This problem limits the choice of materials to be utilized in the heat exchanger construction. Another problem is that the gasket has to be pierced at spaced intervals to receive the clamping bolts, thus enhancing the problem of leakage if an uneven clamping force exists between adjacent bolts. Also, alignment between the holes in the header, tank and gasket complicates the assembly procedures for the heat exchanger.
Other methods of assembly include bending or crimping operations of one or both flanges formed on the header and tank to join and seal the parts together, however, such operations also require a high degree of alignment of parts and complex joining operations. The present invention overcomes the above problems of sealing radiator parts together by providing a simplified joining technique.